Sylvester Stallone is not a stupid man. He himself admitted that his career decisions were increasingly ruled by greed rather than artistic integrity. And in spite of the fact that he was making $20 million-three-picture deals, it was clear from the disappointing box office of "Judge Dredd,"

"Assassins" and "Daylight" and the other recent action films showing him off as the stony, arrogant, self-controlled hero, that he was going to have to alter his image or look for a new line of work.

The offer to play a sweet, soft-bellied, sad-faced underachiever in James Mangold's "Cop Land" must have seemed like a gift from the heavens. There are two characters Stallone knows he can play. One is the cocky, unflappable, stoical superhero. The other is Rocky Balboa (of "Rocky" ), a sweet, soft-bellied, sad-faced underachiever.

The lovable shlub that first made Stallone famous has returned in the form of the "Cop Land" lead character Freddy Heflin, sheriff of Garrison, N.J., where the skyscrapers of New York City across the river stand like the gates to an inaccessible paradise.

Years ago, in the greatest act of heroism of his life, Freddy saved from drowning the beautiful Liz (Annabella Sciorra), who may be seen as the Adrian substitute if you like the "Rocky" analogy. This feat left him deaf in one ear and thus ineligible for service in the New York Police Department. Joey Randone (Peter Berg), a cop, married Liz. Freddy lost his dream girl and his dream job.

Over the years, sleepy little Garrison has become a bedroom community for New York cops, under the leadership of a godfather-like Ray Donlan (Harvey Keitel). He and his gang of fellow officers are on the take, into drugs and murder and intimidation. Freddy, in awe of them, is too honest and naive to see their corruption.

When one of Ray's gang, a young cop called Murray Babitch (Michael Rapaport), shoots and kills a couple of unarmed youths on the bridge between Jersey and N.Y.C., Ray arranges to have Murray seem dead rather than face charges and jeopardize Ray's crooked operation.

Internal Affairs officer Moe Tilden (Robert De Niro) tries to persuade Freddy that helping catch Ray and his thug-cops would finally give him the dignity that he abandoned when he was told he couldn't become one of New York City's finest. He's handing him his title bout, the big fight against Apollo Creed.

Writer-director Mangold's first film was "Heavy," the story of an overweight cook who quietly obsesses over a beautiful young waitress. Mangold's second outing might best be titled "Sluggish." If in the narratively simple

"Heavy" he was able to get away with minimal directorial panache, no sense of pacing, no sense of composition and no discernible talent for creating tension, he has no such protection here.

As the above precis outlines, "Cop Land" presents a fairly involved plot, and Mangold is not equipped to do more than blurt all the information onto the screen and let the nuances settle where they may. "Cop Land" sadly lacks the zip and smartness of other movies about cop corruption, such as "Serpico" and "Prince of the City."

And this is not for lack of trying. Mangold is a self-described artistic calculator. On a recent

"Charlie Rose," he talked about "triangulation," referring to a scene in which Freddy finally offers his services to internal affairs. Moe is at his desk eating a sandwich. Mangold seems to think that the sandwich added a third element to the scene, as a distraction that provided tension. In fact, this scene was as lifelessly directed as most of the scenes in this movie. It was as cliched and emotionally uninteresting as if a bully had kicked sand in Freddy's abashed face. What else is new?

Mangold's calculation is everywhere evident. When Ray's powerful buddies in the police department get the authorities to close down Moe's corruption investigation, you can just see Mangold thinking to himself, "I've got a big star like De Niro in a small part. Better give him a really big scene in which he can rant and rave." And there it is: De Niro, as the frustrated Moe, tearing up his office and yelling at his blameless underlings. It looks like an exercise in acting class, not because De Niro is inadequate, but because his director set him up in a manufactured situation that no amount of talent can counter.

The trouble with "Cop Land" is that it isn't as good as it could have been. In spite of nice work by Ray Liotta as a cop who is tired of being on the wrong side of the law, and a fine, too brief turn by Janeane Garofalo as Freddy's serious young deputy, "Cop Land" ultimately disappoints. The germ of a good movie rests somewhere in this turgid thing, and evidently someone other than Mangold would be required to make that apparent.

Stallone, who put on 40 pounds to properly inhabit the role - and prove that he could do without the burnished image, has reported that he's already received offers to play roles outside of his usual heroic range, and based on his performance in "Cop Land," he deserves the attention.

What's most instructive for students of the ups and downs of moviemaking in all this is that "Assassins" and

"Judge Dredd" were really no worse than the action films of the last few years that did well at the box office, and agreeing to star in them didn't really show bad judgment on Stallone's part. As he well knows, action films aren't made to be worthy. They are made to generate dollars. It's just his bad luck that for some unknown reason, those movies didn't become blockbusters.

"Cop Land," on the other hand, was made with aspirations to artistry. A tip of the hat to the good intentions; it coulda been a contender.